This invention relates to an electroplating apparatus and, in particular, such an electroplating apparatus which comprises means for facilitating mixing and dissolution of a solute in a solvent, and minimising the amount of undissolved solutes to be carried away from a mixing chamber, e.g. into a chamber of the apparatus where electroplating takes place.
According to a first aspect of the invention there is provided an apparatus for mixing a solute in a solvent including a chamber member for containing said solute and said solvent, means adapted to move said solute and said solvent in said chamber member, and at least one divider adapted to occupy a first position to substantially divide said chamber member into at least two portions, and a second position in which said chamber member is undivided, wherein said at least one divider is movable, by the current generated by said moving means, from said second position to said first position. In one embodiment of this first aspect, said means adapted to move said solute and said solvent includes at least a pump member, and at least one first and at least one second pipe member connected with said pump member, wherein said pump member is adapted to draw said solute and said solvent from said chamber member via said at least one first pipe member and introduce said solute and said solvent into said chamber member via said at least one second pipe member. In a sub-embodiment of said embodiment oif said first aspect, said current is generated upon introduction of said solute and said solvent in said chamber via said at least one second pipe member.
According to a second aspect of the invention there is provided an apparatus for mixing a solute in a solvent including a chamber member for containing said solute and said solvent, means adapted to move said solute and said solvent in said chamber member, and at least one divider adapted to move said solute and said solvent in said chamber member, and at least one divider adapted to occupy a first position to substantially divide said chamber member into a first portion and a second portion, wherein when said at least one divider is at said first position, said moving means is adapted to move said solvent in said first portion more vigorously than said solvent in said second portion. In one embodiment of this second aspect, said first and second portions are in a liquid-communicable relationship with each other.
According to a third aspect of the invention there is provided an apparatus for mixing a solute in a solvent including a chamber member for containing said solute and said solvent, means adapted to move said solute and said solvent in said chamber member, and at least one divider adapted to occupy a first position to substantially divide said chamber member into at least two portions, and a second position in which said chamber member is undivided, said at least one divider being biased towards said second position. In one embodiment of this third aspect said divider is biased towards said second position on its own weight. In another embodiment of said third aspect, said bias of the divider towards said second position is counteracted by a current generated by said means adapted to move said solute and said solvent.
According to a fourth aspect of the invention there is provided an apparatus for mixing a solute in a solvent includign a chamber member for containing said solute and said solvent, means adapted to move said solute and said solvent in said chamber member, at least one divider adapted to occupy a first position to substantially divide said chamber into at least two portions, and at least one stopper member adapted to abut said at least one divider when said at least one divider is at said first position, wherein said stopper member is in a substantially reversed V-shaped.
Prior electroplating apparatus is known. An example of prior electroplating apparatus consists of two housings wherein a respective chamber is located therein. A first chamber is for dissolving solutes in a solvent to form an electrolyte solution. The solution is then delivered to a second chamber in which electroplating occurs.
One problem associated with this conventional type of apparatus is that undissolved solute in the first chamber may be delivered, together with the electrolyte solution, to the second chamber. This not only contaminates the second chamber with undissolved solute, which will affect the electroplating process, it is also uneconomical as additional solute is needed to compensate the undissolved solute which is unused for the intended purpose in the second chamber.
Another problem associated with a conventional type of apparatus is that a simple stirring mechanism in the shape of a turbine arranged in a lower portion of the first chamber is often used. This design has a disadvantage in that an undesirably rough current is produced during the dissolution of the solute. Undissolved solute may undesirably be brought to an upper portion of the first chamber by the rough current and carried away from the first chamber.
The present invention seeks to provide an improved mixing apparatus as well as an improved electroplating apparatus which mitigates the disadvantages of the prior art apparatus while affording additional operating advantages.
According to a first aspect of the present invention, there is provided a mixing apparatus comprising a chamber with at least one inlet allowing entry of a solute and a liquid solvent, at least one outlet allowing exit of a solution of the solute and solvent, and at least a separator having at least one generally upwardly facing surface and one generally downwardly facing surface, wherein the surfaces define a passageway allowing the solution to pass through and out of the chamber, and wherein undissolved solute is descendable along the generally upwardly facing surface.
Preferably, the separator may include a plurality of separating members.
Advantageously, each of the separating members may comprise a plate member.
Suitably, each plate member may provide a generally upwardly facing surface and a generally downwardly facing surface.
Preferably, the plate members may be disposed side by side with each other.
Advantageously, the upwardly facing surface and downwardly facing surface may be substantially parallel to each other.
Suitably, the upwardly facing surface and the downwardly facing surface may be slanted at substantially 55-65xc2x0 from a horizontal axis of the chamber.
Preferably, the upwardly facing surface and the downwardly facing surface may be slanted at substantially 60xc2x0 from the horizonatal axis of the chamber.
Advantageously, the mixing apparatus may further comprises means for agitating the solvent with the solute in said chamber.
Suitably, the mixing apparatus may further comprise means for detecting concentration of the solution, wherein the detecting means may be located below the separator.
Preferably, the mixing apparatus may further comprise means for allowing the solute to reach a lower portion of the chamber before being mixed with and dissolved in the solvent.
According to a second aspect of the present invention, there is provided an electroplating apparatus, wherein the electroplating apparatus includes a mixing apparatus as described above.
An embodiment of the present invention is now described, by way of example only, with reference to the following drawings in which: